Re: [9front] WANTED: ip based filtering of incoming connections

[Jacob Moody <moody@posixcafe.org>]

On 7/26/24 19:20, sl@stanleylieber.com wrote:
>>> For anyone following along at home, this has now been fixed in commit 605bed312a0a24db6cce2f7170353351cbddbd2d.
>>
>> i can now successfully block an individual ip:
>>
>> 	168.235.81.125&255.255.255.255
>>
>> or a /24:
>>
>> 	168.235.81.0&255.255.255.0
>>
>> but not a /14:
>>
>> 	47.128.0.0&255.252.0.0
> 
> use of the | separator seems to break filtering for the entire line:
> 
> 	aux/dial -e 'ipmux!ver=4;src=85.208.96.0&255.255.255.0|85.208.98.0&255.255.255.0' >/dev/null &
> 

This is a bit tricky the interface does not quite work how you want it to.
 From the man page:

	 Expr is of the	form:

	      value

	      value|value|...

	      value&mask

	      value|value&mask

You are only allowed a single mask, not a mask per value.
So we take the input, AND it just once and then check if it matches any of the given values.
This is a bit strange, but it does seem to be intentional.